I tried the low tension Labellas and thought they sounded quite different from the regular Labellas. Didn't care for the tone.
I have medium scale LaBella LTF's on almost all my Höfners. Too bright when new but once they're broken in I like them. They're not easy to find in medium scale so when I do find a dealer that stocks them I get a couple extra sets.
For long scale flats, as some of you know, I'm a big fan of Ernie Ball Group IV (
NOT the Slinky flats!). I switched to EB after years of TI JF's. The .040 set is a little stiffer than TI's, and has better tone and feel for my taste. And they cost about half of TI's.